What is the difference in lcd and led in TVs?

What's the difference between LED, LCD, flat screen, and plasma TVs?

• I'm a total noob at technology.... can someone explain what they are and also which one is the best, second best, etc? per dollar? most recent tech? Thanks.

• Answer:

  They are all "flat screens," which is a way of comparing them to old tube-type TVs that were very thick front to back. The differences between plasma, LCD, and LED: Plasma: gas-filled cells are ionized, producing light of varying colors to form the picture. Modern plasma sets produce brilliant pictures, as good as anything else. They're best for fast action sports and game consoles. Takes more electrical power, and physically heavier than equivalent LCD/LED sets. Generally lower cost. LCD: Liquid crystal display, like a digital watch. Voltage is applied to each pixel in a manner that causes it to change color. The older, conventional sets commonly referred to as "LCD" are illuminated from behind by a fluorescent lamp. LCD sets are best in rooms with a lot of ambient light (plasmas have a screen glare problem). Less-expensive models have a fast-motion blur problem, seen with sports and game consoles. (No blurring with plasma.) LED (or "LED-LCD"): Exactly the same as LCD, except that the backlight is a bank of light emitting diodes. There are two types, edge-lit and full matrix. Edge-lit LED sets can be very thin, but otherwise perform pretty much like a very good conventional LCD. Matrix-lit sets can control the contrast in specific areas of the screen, giving better overall picture quality. These sets draw the least electric power and, in theory, have the least risk for maintenance problems, but they are the most expensive of the three types. There are also OLED sets, but they are mainly experimental at present; very small screens, prohibitively costly, and they don't last long. When that technology is fully developed, the LEDs themselves will comprise the picture.